Abstract
The impact of manipulations known to affect configural and featural processing of faces was assessed for human and animal faces. Two experiments were performed where either the features of the face were altered and/or the orientation was changed to assess whether configural or feature information was being used to process the faces. In Experiment 1 the Thatcher Effect was applied to pictures of both human and animal faces and the pictures were presented as either upright or inverted. Observers rated the perceived grotesqueness of the face pictures. Thatcherization resulted in higher ratings of grotesqueness for the human faces than the animal faces, but inversion of the stimuli yielded similar results for both types of pictures. In Experiment 2, spatial distortions were applied to pictures of human and animal faces, and the resulting pictures were rotated to varying degrees. The human face pictures appeared the most grotesque at 0 and 45 deg, and were less grotesque at 135 and 180 deg. The effect of spatial distortion on the pictures of the animal faces was minimal and orientation had relatively little impact on the perceived grotesqueness. The results suggest that the processes used to encode human faces as well as animal faces are on a continuum of facial processing; and that human faces, in particular, are processed using an extreme form of configural processing supporting the theory that human faces are “special” due to the effect of expertise.